type CFG struct {
// Sentinel nodes for single-entry, single-exit CFG. Not in original AST.Entry, Exit *ast.BadStmt// All defers found in CFG, disjoint from blocks. May be flowed to after Exit.Defers []*ast.DeferStmt// contains filtered or unexported fields
}

CFG defines a control flow graph with statement-level granularity, in which
there is a 1-1 correspondence between a block in the CFG and an ast.Stmt.